Temporary Works - BHSEA

1 Temporary WorksJan Andresen BEng CEng MIStructEHM Specialist Inspector of Health and Safety12 October 2012 Doing what's right isn't the problem. It is knowing what's B of Temporary Works Temporary Works means all Temporary Works of every kind (other than contractors equipment) required on site for the execution and completion of the permanent Works and remedying any defects (International Federation of Consulting Engineers (FIDIC) Conditions of Contract Definition) All Temporary Works of every kind required in or about the construction and completion of the Works .

2 (ICE Conditions of Contract Definition)Definitions of Temporary WorksTemporary Works is defined in BS5975 : 2008 as parts of the Works that allow or enable construction of, protect, support or provide access to the permanent Works and which might or might not remain in place at the completion of the Works Alternative Definition: Temporary Works Anything the contractor has to provide or do in order to construct the permanent Works Hoardings Welfare facilities Services Platforms Earth support Access Propping & shoringTemporary Works Topics Earthworks - trenches, excavations, underpinning, piling platforms and cofferdams etc.

3 Structures formwork, falsework, back-propping, fa ade retention, edge protection, re-propping, scaffolding, bailey bridges, hoarding, and signage etc Plant - mobile crane outrigger design, tower crane bases With Temporary Works No planning or procedure. No design or poor design. Lack of competent contractor / developer. No Temporary Works equipment available. Inappropriate use of TW equipment or other non TW equipment being used for the purpose of Temporary creep, the enemy of planningqgcarry out proper investigation of ground conditions, services or adjacent out proper investigation of ground conditions, services or adjacent horizontal and or diagonal bracing to resist lateral (wind) loads.

4 Lack of knowledge and inexperience of persons involved in Temporary Works design / and or changes to an approved Temporary Works planning, by a competent is a Competent person ? A competent person is one who can demonstrate that they have sufficient professional or technical training, knowledge, actual experience and authorityto enable them to:- Carry out their assigned dutiesat the level of responsibility allocated to them. Understand any potential hazardsrelated to the work (or equipment) under consideration Detect any technical defects or omissionsin that work (or equipment), recognise any implications for health and safetycaused by those defects or omissions, and be able to specify a remedial action to mitigate those of hoardingsHoardingsHoardingsMFLH oardingsMFLH oardingsHoardingsProprietary hoardings and fencingPicturesProprietary hoardings and fencing Still the same issues as before (wind / overturning etc)

5 But now designed by manufacturer So does the contractor know / understand the limitations of the hoarding and what the system has been designed to take? Have they installed them correctly? Have they changed things ( sheeted it or added a dirty great big advertising sign?) FencingExcavations basic principles No ground can be relied upon to stand unsupported. depth rule is often quoted on site but went years ago. Steps shall be taken where necessary to prevent danger to any personHSE enforcement expectations for excavations Prior to C(HSW) 1996 all excavations in which someone was working required shoring C(HSW) 1996 Risk assessment based approach not intended to impose lower standard CDM 2007 contains old C(HSW)

6 Provisions Excavation deeper than being worked in without shoring Prohibition Notice unless justified by suitable & sufficient risk assessmentSoils fail in different waysStiff clay Soft claySoils fail in different waysSand Basement / Deep underpinning construction High Risk work Need Temporary Works engineering input Method Statement should be in place Clear method of shoring excavations In poor soils - will need sacrificial back shutter HSE/ Bldg Ctrl Interface Dangerous Structures Underpinning failure to survey existing wall and to propExternal wallInternal wallHeading construction (Design and Management) Regulations, 2007 Regulation 31 (1) All practicable stepsshall be taken, where necessary to prevent danger to any person, including, where necessary, the provision of supports or battering, to ensure that (a) any excavationor part of an excavation does not collapse; (b) no material from a side or roof of, or adjacent to, any excavation is dislodged or falls.

7 And (c) no person is buried or trapped in an excavation by material which is dislodged or (Design and Management) Regulations, 2007 31 (2) Suitable and sufficient steps shall be taken to prevent any person, work equipment, or any accumulation of material from falling into any excavation 31 (3) Without prejudice to paragraphs (1) and (2), suitable and sufficient steps shall be taken, where necessary, to prevent any part of an excavation or ground adjacent to it from being overloaded by work equipment or material;(source E Little The building of the Barton High Level Bridge) Temporary WorksBarton Bridge disaster 1959 Whilst erecting 4No, 200 ton steel girders, 80ft above the ground, the supporting scaffolding collapsed bringing down the girders and killing 4 men.

8 60 men, that would normally have been on the girders, were lining up for their pay at the children were left fatherless. (source E Little The building of the Barton High Level Bridge) Temporary WorksEvidence given at the Inquest:Scaffolding not installed in accordance with the design drawingsThe design drawing was not a working drawing and only gave an indication of the structureWorn and corroded scaffold tubes had been used (source E Little The building of the Barton High Level Bridge) Temporary WorksLack of lateral bracingDesign carried out by an estimator draughtsman.

9 Not passed by an engineer Bulging of the scaffold noted but not acted upon(source E Little The building of the Barton High Level Bridge) Temporary WorksTragedy struck againScaffold supporting 4 steel girders, 250ft long failed, killing 2 workers and injuring 8 others. (source E Little The building of the Barton High Level Bridge) Temporary WorksThe Coroner concluded that ..the general picture was one of men fumbling about not knowing where anything was, or where to get (source E Little The building of the Barton High Level Bridge) Temporary WorksThat was 50 years ago this wasn Works guidance SIM 02/2010/04 The management of Temporary Works in the construction industry BS 5975:2008 Code of practice for Temporary Works procedures and the permissible stress design of falsework BS 5531.

10 1988 Code of practice for safety in erecting structural frames (Withdrawn but gives useful advice) Temporary WorksSo what does the law require? Temporary Works guidance Foreword to BS 5975:2008 states: The term Temporary Works co-ordinator (TWC) has been adopted to reflect the need for procedural controls of all Temporary Works and to recognise that the majority of contractors already control Temporary Works in this manner. Compliance with the construction (Design and Management) Regulations 2007 (CDM) [3], [8] has been incorporated, particularly in respect to the interface between the design of permanent worksandthedesignoftemporaryworksTempora ry Works guidance CDM applies to all design requirement for the design of the Temporary Works to be co-ordinated to ensure that the risks are properly controlled.